Some of conventional wireless ultrasonic diagnostic apparatuses wirelessly transmit echo data obtained by an ultrasonic probe to the main device (see Patent Literature 1, for example).
FIG. 1 shows a structure of a conventional wireless ultrasonic diagnostic apparatus 10 disclosed in Patent Literature 1. A scrambler 112 shown in FIG. 1 scrambles echo data using either unique data identifying a main device 200 or unique data identifying an ultrasonic probe 100. More specifically, the scrambler 112 scrambles serial data provided by a PS conversion unit 110, using either a code signal provided by a code signal generator 114 for identifying the main device 200 or a code signal provided by the code signal generator 114 for identifying the ultrasonic probe 100. Then, the scrambler 112 provides the scrambled data to a modulator 116.